Mpemba Effect- the Effect of Time

This paper draws the following conclusions on the nature of time by analyzing the relationship between time and speed, the relationship between time and gravitational field, the gravitational redshift of the photon, and the black-body radiation theorem: Time on an object is proportional to the amount of energy flowing out (or in) per unit time (observer’s time) per unit surface area of the object. When an object radiates energy outward: t'=μB(T) =μσT 4=μnhν/st Where t’ is the time on the object, μ is a constant, B(T) is the radiosity，the total energy radiated from the unit surface area of the object in unit time (observer’s time), σ is the Stefan-Boltzmann constant, T is the absolute temperature, n is the number of the photons radiated, ν is the average frequency of the photons radiated, s is the surface area of the object and t is the time on the observer. When the object radiates energy outward, the higher the energy density of the space (for example the stronger the gravitational field of the space), the smaller the radiosity B(T) of the object in the space, the longer the average wavelength of the light quantum emitted by the object, the slower the time on the object, the longer the life of the system. When the object radiates energy outward, the faster the object moves relative to the ether, the higher the energy density of the local space in which the object is located, the smaller the radiosity B(T) of the object, the longer the average wavelength of the light quantum radiated by the object, the slower the time on the object, and the longer the life of the system. When the object radiates energy outward, the higher the temperature of the object, the greater the object's radiosity B(T), the shorter the average wavelength of the light quantum radiated by the object, the faster the time on the object, and the shorter the life of the system. Applying the above conclusions about the nature of time, the author analyzes the Mpemba effect and the inverse Mpemba effect, and reaches the following conclusion: the Mpemba effect is the time effect produced when heat flows from objects into space, and the "inverse" Mpemba effect is the time effect produced when heat flows from space into objects.

Erosion Corrosion of Drill Pipe During Drilling Operations

The presence of high rotating speeds and weights, the corrosiveness of water-based drilling muds, and high-speed mud with embedded cuttings, exposing drill string components to severe wear and corrosion that reduce their service life. The drill pipe erosion, abrasive wear and corrosion depend on properties of drilled cuttings and drilling fluids. Any variation in these properties leads to change in pipe degradation rate. There is a need to study the effect of individual factors, for expecting the drill pipe series life and to find a solution to this challenging problem. This research aims to evaluate the influence of real rock cuttings sizes and concentration as well as we investigate the effect of base fluid type on the erosion-corrosion rate. Actual drilled cuttings have been sieved to get three sizes of erodent cuttings; namely, 0.841 to 3.3 mm. Experiments are done with three sand concentrations (5%, 10% and 15%). The rate of erosion-corrosion of the drill pipe specimens is measured as the loss of weight per unit surface area per unit time under the dynamic action of solid particles. The eroded surfaces of the specimens are examined using Scanning Electron Microscopy (SEM) to visualise the impact of the drill cuttings at various conditions. It is seen that the rate of corrosion/erosion decreases with the increase of drilled cuttings concentration. Also, high erosion-corrosion rate is detected in situation of large drill cuttings particles. In this research, we explored a novel simple technique to simulate pipe erosion-corrosion in a reservoir-like environment. Furthermore, this paper proposed a new approach to control drill pipe erosion-corrosion by using SiO2-nanofluid.

Deposition Characteristics of Firebrands on and Around Rectangular Cubic Structures

The focus of the present work is on the deposition of firebrands in a flow over a rectangular cubic block representative of a structure in wildland-urban interface (WUI). The study was carried out by physics based modeling where the wind flow turbulence was dealt with by large eddy simulation (LES) and firebrands were treated by Lagrangian tracking. The Lagrangian equations coupled with the flow solver, accounted for both translational and rotational motions as well as thermochemical degradation of firebrands, assumed to be cylindrical. The dimensions of the structure were varied from 3 to 9 m in the simulations for a parametric study. The simulations were carried out by tracking many firebrands randomly released with a uniform distribution from a horizontal plane 35 m above the ground into the computational domain. The coordinates of the deposited firebrands were used to calculate their normalized number density (number of landed firebrands per unit surface area) to quantify their deposition pattern. On the leewardside of the block, an area, referred to as the safe zone, was identified right behind the structure where firebrands never deposit. The size of the safe zone in the direction perpendicular to the wind was nearly identical to the width of the structure. The length of the safe zone in the wind direction was proportional to the height of the structure. The leeward face of the blocks was never hit by a firebrand. The windward face was hit by many more firebrands than the lateral faces but much less than the top face. The distribution of the number density of the deposited firebrands on the top face was found to be correlated with the flow separation and reattachment on this face.

Jointed Plain Concrete Pavements in Airports: Structural–Economic Evaluation and Proposal for a Catalogue

Although the design of jointed plain concrete pavements could be solved by commercial software, there is still a need for simple tools to be used in feasibility studies and preliminary cost–benefit analyses. This paper analyzed and verified jointed plain concrete pavements for airports composed of square slabs without tie and dowel bars. The examined slabs are laid on a cement-treated base layer and a stabilized granular subbase layer. The finite element software FAARFIELD was used to design the JPCP pavements when they are subjected to the design of the airplane (i.e., turboprop C-130J Hercules) under different conditions. Seven subgrade load bearing capacity values, twenty traffic levels, and two construction hypotheses (i.e., constant or variable thickness of the two deeper layers) were designed and then verified with the Westergaard theory in order to present a proposal for a catalogue. Finally, the construction cost per unit surface area was calculated for different construction methods of paving (by slip form paver or by fixed form). The obtained results provide a simple and fast procedure to design preliminary airport JPCPs.

OBTAINING BIODEGRADABLE COMPOSITE MATERIALS BASED ON POLYOLEFINS AND HUSK OF SUNFLOWER SEEDS

The paper presents the results of a comparative study of physical and mechanical, rheological, and biodegradable characteristics of a mixture containing low- and high-pressure polyethylene (HDPE 273-83 and HDPE 15303-003, respectively) in a 1:1 ratio filled with finely ground (less than 200 microns) sunflower husk (5-30% by weight). The mixture also contained 10% compatibilizer (functionalized by the method of alkaline alcoholysis of sevilen (SEVA 12206-007) and 1% of technological additive (polyethylene glycol (PEG-115 (4000). It has been established that as the content of the plant filler increases (up to 25%), the elastic modulus and tensile strength has not practically changed. The relative elongation of the composite under tension exceeds 100% (with a sunflower husk content up to 15% by weight). The complex viscosity and shear modulus of the considered melts with different filler contents are almost at the same level. The introduction of sunflower husk (up to 30%) and compatibilizer (10%) helps to reduce the viscosity and elasticity of the melts, which is evidence of a significant improvement in the processability of the compositions compared to HDPE 273-83. For a comparative assessment of composites biodegradability, moisture absorption, chemical oxygen consumption, and composites mass loss in laboratory soil during exposure for 12 months were being studied. It is shown that with increasing filler content, the ability of composites to biodegradation increases. In addition, it was found that the indicator of chemical oxygen consumption per unit surface area of the sample is a more productive and reproducible estimate in comparison with traditional methods for assessing the degradability of composite materials.

Effect of activation temperature on surface basicity of natural aluminosilicates

Montmorillonite and nontronite are layered aluminosilicates of smectite group minerals widely demanded in many industries owing to their unique physical-chemical and other properties. By thermal activation of raw clays there are variations in their porosity, surface area and physical-chemical properties, including formation and redistribution of surface active site of acid-base or redox character. The aim of present studies included investigation of the effect of thermal activation on the character of distribution and a number of basic sites on the surface of natural layered aluminosilicates by means of the new method of inverse thermoprogrammed desorption of СО2. Samples of natural aluminosilicates rich in montmorillonite (Montmorillonite 67%, illite 5%, quartz 5%, feldspars 21%) and nontronite (nontronite 70%, illite 10%, kaolinite 5%, quartz 10%, feldspars 8%) were characterized by XRD, XRF, BET N2 adsorption techniques. To probe surface basicity and determine the number of basic sites a new iTPD-CO2 was used. Prior the iTPD-CO2 measurement 100 mg of a sample was activated at 200, 300, 400oC, then cooled down and loaded with CO2 (3ml/min flow rate of CO2 for30 min). Next, the reactor was flushed by 5 ml/min N2-flow to desorb weakly sorbed CO2. The iTPD-CO2 profiles were recorded within 20-800oC at a 20oC/min heating rate and treated using ChemStation software. The experimental profiles of CO2 desorption for Mt and Nt samples observed two temperature regions. Low temperature peaks evolved around 80-90oC for Mt and between 110-127oC for Nt were most likely related to the weak basic sites, whereas high temperature peaks around 510 and 620oC for Mt and above 320oC for Nt testified to stronger ones. The reasoning of the obtained iTPD-profiles was done considering thermal behavior of layered aluminosilicates. The total basicity of Nt and Mt samples was 359.2 and 209.9 mmol/g respectively. The 1.6 times higher basicity of Nt was, obviously, caused by its phase and chemical composition and developed surface area and porosity. At higher activation temperatures the number of weak basic sites related to hydroxyl groups of adsorbed water molecules gradually decreased, namely, by 21 times for Mt and by 2.8 times for Nt. Dehydroxylation of structural Al-OH, Fe-OH, Mg-OH above 200oC, which becomes irreversible above 300oC, provided formation of residual oxygen atoms and their contribution to population of stronger basic sites. In accordance with thermal behavior of dioctahedral smectites, is assumed that strong basic sites of Mt are trans- and cis-vacant Al-OH groups dehydroxylating correspondingly at ~550 and 650oC. Fe-rich sample of Nt rapidly lost hydroxyls at rather lower temperatures that resulted in more heterogeneous distribution of strong basic sites of varying strength. At higher activation temperatures the ratio of stronger sites number to weak sites increased from 23 to 200 for Mt, whereas for Nt this ratio varied between 54-67 times. In general, total basicity of Mt and Nt decreased by 2.2-2.3 times as a result of their dehydration and dehydroxylation by thermal activation. The normalized values of basicity per unit surface area (BΣ/S, mmol/m2) were 1,5 times higher for Mt surface, testifying to higher occupancy and density of active sites for Mt than that of Nt.

Adsorption of p-Arsanilic Acid on Iron (Hydr)oxides and Its Implications for Contamination in Soils

Because of the diversification of industries in developing cities, the phenomenon of the simultaneous contamination of various kinds of pollutants is becoming common, and the environmental process of pollutants in multi-contaminated environmental mediums has attracted attention in recent years. In this study, p-arsanilic acid (ASA), a kind of organic arsenic feed additive that contains the arsenic group in a chemical structure, is used as a typical contaminant to investigate its adsorption on iron oxides and its implication for contaminated soils. The adsorption kinetics on all solids can be fitted to the pseudo-second-order kinetic model well. At the same mass dosage conditions, the adsorption amount per unit surface area on iron oxides follows the order α-FeOOH > γ-Fe2O3 > α-Fe2O3, which is significantly higher than that for actual soil, because of the lower content of iron oxides in actual soil. Lower pH conditions favor ASA adsorption, while higher pH conditions inhibit its adsorption as a result of the electrostatic repulsion and weakened hydrophobic interaction. The presence of phosphate also inhibits ASA adsorption because of the competitive effect. Correlations between the amount of ASA adsorption in actual soil and the Fe2O3 content, total phosphorus content, arsenic content, and organic matter content of actual soil are also investigated in this work, and a moderate positive correlation (R2 = 0.630), strong negative correlation (R2 = 0.734), insignificant positive correlation (R2 = 0.099), and no correlation (R2 = 0.006) are found, respectively. These findings would help evaluate the potential hazard of the usage of organic arsenic feed additives, as well as further the understanding of the geochemical processes of contaminants in complicated mediums.

Analysis of quality and prediction of external and internal egg traits in Mexican native turkey hens

This study aimed to evaluate external and internal quality traits and determine prediction equations for some of these traits in eggs of Mexican native turkey hens. A total of 72 eggs from native turkey hens in the laying stage raised in rural municipality of Villaflores, Chiapas were measured. The external traits evaluated were: egg weight (EW), polar diameter (PD), equatorial diameter (ED), egg shape index (SI), shell weight (SW), shell percentage (SP), egg surface area (ESA) and shell weight per unit surface area (SSA). The internal traits were: albumen height (AH), yolk height (YH), albumen weight (AW), yolk weight (YW), Haugh units (HU), albumen percentage (AP), yolk percentage (YP) and yolk color (YC). The data were analyzed with descriptive statistics and Pearson correlation coefficients (r) and linear regression using the SAS program, ver. 9.4. The values obtained for the external egg quality traits showed greater variability. Pearson's correlation coefficients between external and internal traits were positive and moderately significant (P <0.05), as well as highly significant (P <0.0001), and ranged from r = 0.31 (EW vs PD) to r = 0.99 (ED vs ESA). All linear regression equations to predict EW, SW, AW and YW were found to be significant (<.0001). The best predictors of EW were PD, SI, SW and ESA (R2 = 76%). SW and YW traits can be adequately predicted using the EW and SI values together (R2 = 59% and R2 = 74%, respectively), while the AW can be predicted from the EW (R2 = 33%). Based on the results obtained, it is suggested to implement selection programs to improve the quality parameters of the native turkey hen egg in Mexico.

Physiological Bases of Magnetoencephalography and Electroencephalography

Understanding the physiological bases of magnetoencephalography (MEG) and electroencephalography (EEG) provides the foundation for developing these techniques as tools for studying human brain functions because this information can serve as a guide for planning experimental studies and for interpreting the data. During the past 50 years, the concept of electrophysiology of neurons has been profoundly modified as new types of active conductance have been discovered in the dendrites and soma. The biophysical models of individual neurons and neuronal networks developed within the framework of modern electrophysiology have provided quantitatively accurate accounts of evoked magnetic fields, extracellular potentials, and intracellular potentials in principal neurons in the tissues within a single theoretical framework. These results are consistent with the conclusion that intracellular currents in active tissues produce both MEG and EEG signals in the cerebellum, hippocampus, and cerebral cortex. We now know that the calcium and potassium currents are the major currents shaping the waveforms of MEG and EEG and that the sodium and potassium currents generate the spikes and high-frequency signals detectable outside the brain. The current dipole moment density, defined as current dipole moment per unit surface area of the active cortex, is governed by the intracellular volume fraction and basic kinetics of the active conductances. This quantity, which is conserved across the evolutionary scale ranging from reptiles to humans, may serve as a useful physiological constraint in interpreting MEG and EEG signals. It is hoped that this foundation will help advance the research on human brain functions.

Ferrofluid thin films for aerofoil lift enhancement and delaying flow separation

ABSTRACTIn this work, consideration is given to a novel concept for aerofoil lift enhancement and delaying flow separation. Here, lift enhancement is attained by preventing the growth of the boundary layer through the elimination of the zero-slip condition between the wing surface and the air stream. The concept would simulate all the effects of a moving wall, leading to the appearance of a slip velocity at the gas–fluid interface, including the injection of momentum into the air boundary layer, but with one exception: here there is no moving wall but instead a ferrofluid thin film pumped parallel and attached to the wall by a magnetic field. Utilising a simplified physical model for the velocity profile of the ferrofluid film and based on ferrohydrodynamic stability considerations, an analytical expression for the interfacial velocity is derived. Finally, from the available experimental data on moving walls, the expected lift and angle-of-attack enhancement are found as well as the weight penalty per unit surface area of the wing is estimated. Additional research and development is required to explore the possibilities of using ferrofluid thin films.